Hammer unit for grinding mills



April 9, 1940. w. J. CLEMENT HAMMER UNIT FOR GRINDING MILLS Filed Nov. 23, 1938 Ill INVENTOR WALTER JCLEMENT' ATTO RN EYS ,4 Patented Apr. 9, i940 2 end of which was mounted upon the same pivot.

,PATENTLI'QFFICE.

-n 'mnunn. UNIT FOR GRINDING mus Walter J. CiementQNew Hartford, N. Y., assignor to- The Bossert Company, Inc.. Utica, N. Y., a

corporation of New York Q 'Application November 23, 1938, Serial No. 241,884

" 7. Claims. (01. 83-11) My present inventionrel'ates to a rotary hammer grinding mill and more particularly to the hammer unit for such a grinding mill.

The purpose of my present invention is to provide a new and'improved form of hammer unit for a rotary hammer grinding mill and more particularly to-provide an article of the class de-' scribed which is simple in construction, new, (at-- [active and reliable in operation and one wherein new and improved means are provided for more readily changing the position of hammer head relative to the supporting plates thereof.

In the construction of the hammer unit shown in my former patent upon a rotary hammer grinding mill issued July 31, 1928, Patent No. 1,678,723, there was provided a locking member the inner shaft as carried the two hammer-supporting plates while the radially outward end of said locking member had a notched recess into which fitted any one of the several projections and corresponding notches of the hammer head. When that unit was once assembled the hammer head was locked from rotation relative to the locking member and the hammer-supporting side plates but the hammer head could not be moved to a new'position without disassemblingthe hammer unit to the extent of withdrawing the pivot shaft from at least one of the hammer supporting side plates and the locking member, so as to temporarily retract the locking member from the hammer head, or so as to swing the locking member and hammer part way on the hammer pivot and then retract the locking member from its engagement with'the hammer sufliciently to allow the hammer to be rotated to the desired new position. Thereupon the locking plate or member would'be re-engaged with the now newly located projection upon the hammer head and the inward end of the locking plate re-aligned with the axis of the pivot shaft which holds the unit to the rotary drum of the hammer mill, and then the pivot shaft inserted through the hole in the looking member and in one or'both of the supporting plates of the unit, according to how far the disassembling process had been carried on. The great extent to which the hammer unit of that construction had tobe disassembled in order to struction that upon removing or partly retracting a small member hereafter called fa. keeper or holding bolt. the said main locking bolt may be temporarily moved inwardly to be disengaged from the hammer head without removing the sald locking bolt from the pivot shaft and without withdrawing the pivot shaft from the supporting plates or from any of the rotary drums. In .cne

modification of my invention the said locking bolt may have its inner end swung away laterally from the pivot shaft so as to move the locking bolt inwardly out of engagement with the hammer head and be again replaced in position after a. new adjustment is made, but all without disengaging the hammer-supporting plates from the pivot shaft and so within the scope and terms of this present invention as hereinafter described.

Further purposes and advantages will appear from the specification and claims herein.

Fig. 1 is a top view of a fragment of a. rotary hammer mill embodying this invention and show-' ing one of the hammer units of my present invention with the top edge in view.

Fig.2 is an oblique projection of a hammer unit of this invention but with most of the near hammer-supporting plate removed and with certain parts of the unit shown in section on'line 2-2 of Fig. 1 along the line of the near side of the hammer head and the sliding locking bolt.

Fig. 3 is a side elevation of the hammer unit shown in Figs. 1 and 2, but with all of the near hammer-supporting plate removed and with the keeper bolt removed and withthe sliding locking bolt slid inwardly radially of the hammer mill sufliciently to allow the hammer head to be rotatedysaid hammer head being shown rotated part way to a new position;

Fig. 4 is a side elevation upon a reduced scale of one of the supporting plates I, used in my unit.

Fig. 5 is a side view of the keeper or holding bolt 25.

Fig. 6 is a side elevation on a much smaller scale of the locking member used in the construction'of my said prior patent.

Figs. 7 and 8 are sectional views through a modified form of my invention with the near hammersupporting plate removed and certain parts shown in section upon the line of the near side of the hammer head 3. In Fig. 7- the parts are shown in the position they occupy when the movable lockingbolt 24 is in locked position and in Fig. 8 the movable locking bolt and hammer head are in intermediate position with the locking bolt disengaged from the pivot shaft 4 but not disengaged from the hammer head 3. 1

Referring to the drawing in a more particular description and first to the form of my invention as shown in Figs. 1 to 5, it will be seen that the hammer mill herein shown includes several spaced rotary discs 6 rotated positively in unison by being mounted upon a single shaft not shown but of common construction, a series of spaced pivot shafts 4 of which only one is shown as piercing the twodiscs 6 shown in Fig. 1. Upon a length of the pivot shaft 4 there is mounted a spaced pair of hammer-supporting plates l by holes near the inner end of said plates being pierced by said pivot shaft and forming means for swingingly mounting the said plates for partial rotation upon the pivot shaft in" the usual manner. Towards the outer end of'said plates I there is mounted the pivot 2 and upon the middle length ll of this pivot in the space between the said plates i there is provided the hammer head 2 which is adapted to be rotated upon said pivot. The hammerhead is a relatively heavy block of suitable hard metal and has spaced outer faces I here shown as four innumber, said,

flat faces being the outward part of the main projections upon the said hammer head, and between these main projections are intervening notched portions II. The hammer head is provided with a centrally located transverse opening l2 which revolubly fits upon the central and preferably enlarged diameter portion l3 of the pivot 2. The rotary hammer mill and the hammer unit so far described are common to the construction shown in my said previous patent andto my present constructiom By assuming that the one-piece locking member of my said previous patent, which locking member is shown herein in Fig. 6 be substituted for the movable or slidable locking bolt 24 of my present invention as shown in Figs. 1 and 2, it will be seen that said old locking member 20' cannot be disengaged from the hammer head 3 without disassembling the unit to the extent hereinbefore outlined, with the resulting disadvantages also above outlined and not needing to be repeated at this time. The trouble was that the old locking member 20 of Fig. 6 was so closely fitted to the pivot shaft 4 that the old locking member could not be disengaged from the hammer head without removing the said pivot shaft.

Referring now to my present invention and first to the form thereof shown in Figs. 1-3, it will be seen that my locking device comprises the movable or slidable locking bolt 24 and a relatively smaller member 25 conveniently called a keeper or holding bolt. The movable or slidable locking bolt 24 has much the same outline as the old locking member in that at its outer end it has a recess 2| complementally formed to mate the faces of the hammer head, there being an inner end face 22 to match the main flat faces ill of the hammer, and with said locking bolt having stepped faces 23 at either side of the face 22 to match the steps ll of the hammer head, as most plainly shown in Figs. 2 and 3. Near its inner end the locking bolt 24 has an elongated slot 26. This slot is of a width equal to the diameter or thickness of the pivot shaft 4 and receives said shaft therethrough but the slot is substantially longer than the thickness of said pivot shaft. The parts are so proportioned and the said elongated slot 26 is so located that when the recess 2| in the outer end of the locking bolt 24 is in full locking engagement with one. of the pro- :lections upon the hammer head having the outer face Ill, the inner or left hand end 21 of slot 26 will be in engagement or in substantial engagement with the pivot shaft 4, which relative position being the locking position of said bolt is shown in Fig. 2. Suitably placed between the outer or right hand end 22 of the slot 26 as seen in Figs. 2 and 3 and the recessed outer end of said locking bolt the said locking bolt is provided with a transversely extending circular hole 26 and opposite to this hole when the locking bolt is in locking position as shown in Fig. 2 there are provided in both of the supporting plates I the aligned holes 20 and II. The hole 20, say inthe near plates as shown in Fig. 1, is of the same size as the hole 26 in the locking bolt and not threaded, as is the case with the hole through the locking bolt, but the hole 3| in the other supporting plate is screw-threaded. When the locking'bolt 24 is in this locking position a keeper or holding bolt 26 is inserted through the near plate and through the locking bolt and the screwthreaded end 26' of said keeper or holding bolt 25 is screw-threaded into the aligned screwthread'ed hole 2| provided in the farther or second plate. It will be obvious that mechanically equivalent means can be provided to thus lock the movable or slidable locking bolt in its locking position relative to the hammer head and the holding plates I, and I do not mean to have my invention limited by the precise form or cooperation of the said keeper or holding bolt. The essential construction is that the movable or sliding locking bolt be of such construction as to move back from the hammer head without having to remove the pivot shaft 4 from even one of the supporting plates I, and in this form of my invention even from disengaging the inner end of the locking bolt from its position straddling the said pivot shaft 4. It will now be seen that in the locking position of the movable bolt 24 the hammer head is securely locked from rotation relative to the supporting plates l and the inner end of said locking bolt is mounted about the said pivot shaft 4 and preferably the inner end 21 of said slot 26 is in fairly close engagement with the said pivot shaft 4 so that there will be no tendency for the inner end of the movable locking bolt to shift or rattle relative to the said pivot shaft 4. It will now be seen that the keeper or holding bolt is readily removable and replaceable from the hammer assembly as by retracting the said keeper or holding bolt 25, as by means of a screw-driver or similar tool engaging the slotted end 25 of said keeper bolt until the screw-threaded end of the said keeper will be far enough retracted so as to be clear of the looking bolt 24, and'will conveniently be entirely withdrawn from the other or near supporting plate so as not to be lost or go down into the grinding chamber of the grinding mill while this particular hammer head is being re-adjusteo. As the keeper 25 has been disengaged from the locking bolt 24 the said locking bolt will be moved radially inward of the mill or towards the left hand side as the parts are shown in Figs. 1 to 3, inclusive, and the locking bolt 24 will be brought to the positon shown in Fig. 3. That is the elongated slot 26 allows the said locking bolt 24 to move inwardly while still mounted upon the pivot shaft 4 until the recessed outer end of said looking bolt is retracted far enough from the hammer head to allow the formerly engaged projection of the hammer head to be swung one side or the other of the outer end of the locking bolt until a new position of the hammer head is arrived at with one projection pointing radially outward and its opposite projection pointing radially inward so as to engage in an obvious manner the recessed outer end of this lockin bolt 24 when the locking bolt is again moved outwardlyto locking position. When the said locking bolt 24 has been again moved to outward and locking position the keeper bolt 25 will be again inserted in place and the adjustment of this unit will be thus completed. It will be seen that the whole adjustment is made without removing the locking bolt from the pivot shaft 4 and with out having to remove the pivot shaft 4 from the locking bolt 24 or either of the holding side plates I of this hammer unit. As the .hammer units are ordinarily freely pivoted upon the pivot shaft 4 it will be seen that any particular hammer unit may be swung upward away from the other hammer units ordinarily mounted upon the pivot shaft 4, so that the several hammer units upon a single shaft 4 may be one at a time put into the most convenient position to be adjusted and can be adjusted independently of other hammer units on the same pivot shaft, and particularly the ad justment of any one hammer of a series or of the several hammers in the series can be made without demounting all or any of the hammer units from the hammer mill in order to make the adjustment of the hammer heads in the units.

In Figs. 7 and 8 there is shown one modified form of my invention in that the movable locking bolt 32 while having the general outline of the locking bolt 24 and having its outer end recessed the same as already described and having the keeper hole 33 substantially as already described, has an open-ended slot 34. The inner end 34- of this slot is substantially in the middle transversely of the locking bolt 32 and the whole slot 34 is wide enough to straddle the pivot shaft but the slot 34 extends from its middle end 34 outwardly and as seen in Figs. 7 and 8 upwardly towards the upper edge of the inner end of said movable bolt 32 but upon a slightly curved path ,curving towards the outer end of the said locking .bolt as the slot extends upwardly so that when the keeper bolt of this construction is disengaged from the keeper hole 33 of the locking bolt 32 the said locking bolt 32 may be swun downwardly from the locking position shown in Fig. '7 to the released position shown in Fig. 8. In this released position it will be seen that the inner end of the locking bolt 32 has been swung downwardly until the said slot 34 clears the pivot bolt 4 and in the meantime the hammer head 3 has been swung on its pivot to a corresponding fraction of a revolution until the parts come to the relative position shown in Fig. 8. Thereupon the locking bolt 32 is disengaged from the hammer head by retracting the locking bolt 32 from the hammer head as most conveniently by moving the said locking bolt inwardly or to the left until the hammer head is free to be rotated to the desired new position. Thereupon the looking bolt 32 is again brought into the relative position shown in Fig. 8 with its recessed outer end engaging the now opposite projection of the hammer head and thereafter the said locking bolt 32 together with the hammer head 3 is swung upwardly at the left hand side while the slot 34 rides along the pivot shaft 4 until the said shaft is again housed in the inner end 34" In this modification of the invention it will be seen that the several hammer units may have their hammer heads adjusted entirely independently of any adjustment or dislocation or demounting of any of the hammer units and that the adjustment may be made without withdrawing the pivot shaft of this unit from either or both of the hammer supporting plates 35. While in the adjusting position of this locking bolt 32 it is disengaged from the pivot shaft 4, the engagement of the hammer supporting plates with the pivot shaft 4 is not in any wise interferred with. When this modified form of hammer unit embodying my invention is again in looking position the inner end 34 of the slot 34 will be snugly engaged with the pivot shaft 4 and so will carry the tension or strain of centrifugal force due to the ordinary rotating movement of the unit in a manner common to such grinding mills. The keeper or holding bolt 25 is fully able to stand any strain sidewise or laterally of the said locking bolt 32 especially as the open ended slot 34 will be so placed and the locking bolt 32 so located that the closed end of the slot 34 will be caused to hook or engage the shaft 4'when the grinding mill has its hammers moving in the direction indicated by the arrow at the right hand of Fig. 8.

What I claim as new and desire to secure by Letters Patent is:

1. A hammer unit for a grinding mill comprising a pivot shaft, a pair of spaced hammersupporting plates pivotally mounted at their inner ends on said pivot shaft, a hammer head revolubly mounted between the outer ends of said plates and having spaced symmetrical projections on its periphery, a locking bolt movably mounted between said plates with its outer end recessed to lockingly receive therein the projection of the hammer head opposite thereto, the

inner portion of said locking bolt having an opening into which said pivot shaft fits at locking position of said bolt and having an elongation of said opening allowingsaid bolt to be moved relative to the pivot shaft until the outer end of the locking bolt may be disengaged from said hammer head and a keeper normally rigidly connecting the rocking bolt and the supporting plates when the locking bolt is in locking position relative to the hammer head but adapted v to be detached and permit the said locking bolt tion of said locking bolt having an opening into which said pivot shaft fits at locking position of said bolt and having an elongation of said opening allowing said bolt to be moved relative to the pivot shaft until the outer end of the locking bolt may be disengaged from said hammer head and a holding bolt detachably inserted through the intermediate portion of the supporting plates and of the locking bolt to rigidly connect them when the locking bolt is in extended and locking position but adapted to be removed and permit the locking bolt to be removed to non-locking position.

, 3. A hammer unit for a grinding mill com ing a pivot shaft, a pair of spaced hammer-supporting plates pivotally mounted at their ends on said pivot shaft, a hammer head adjustably mounted between the outer ends of said plates and having spaced working faceson its periphery, a locking bolt movably mounted be-'- werend aw w lockingly {er'igageifltthe adjacent portion of .the

tween said plates-with its hammer headf iwh'en desired working face is in working'fposition, the inner portion of said locking bolt-having an opening into which said pivot shaft fits at locking'position of said bolt i adjustably mountedbetween the outer ends of said plates and? having spacedworking faces on its periphery -a locking bolt -=slidingly mounted between said plates with its outer end shaped to lockingly engage the adjacent portion of the hammer head when the desired working face is in working position, the inner portion of the locking bolt having a longitudinally extending elongated slot through which the said pivot shaft extends, the inner end of said slot engaging the said shaft when said locking bolt is in outward position with its outer end lockingly engaging the adjacent portion of the hammer head, said slot allowing the said locking bolt to be moved inwardly until its recessed outer end becomes disengaged from the hammer head but without the locking bolt being disengaged from the said shaft, and a releasable holding member normally rigidly connecting the locking bolt and at least one of said hammer-supporting plates when the locking bolt is in outward locking position but adapted to be released and allow the locking bolt to be retracted to non-locking position.

5. A hammer unit for a grinding mill comprising a" pivot shaft, a pair of spaced hammersupporting plates pivotally mounted at their inner ends on said pivot shaft, a hammer head adjustably mounted between the outer ends of said plates and having spacecl working faces on its periphery, a locking bolt slidingly mounted between said plates with its outer end shaped to lockingly engage the adjacent portion of the hammer head when the desired working face is in working position, the inner portion of the locking bolt having a longitudinally extending eongated slot through which the said pivot shaft extends, the inner end of said slot engaging the said shaft when said locking bolt is in outward position with its outer end lockingly engaging the adjacent portion of the hammer head, said slot -'allowing the said locking bolt to be moved inwardly until its recessed outer and becomes disengaged from the hammer head but without the locking bolt being disengaged from the said shaft,

and a holding bolt detachably inserted through the intermediate portions of the supporting plates and of the locking bolt to rigidly connect them when the locking bolt is in extended and locking position but adapted to be removed and permit the locking bolt to be moved to non-locking position. and having an elongation of said opening allowa ing said bolt to be moved relative to the pivot 6. A hammer unit for a grinding mill comprising a pivot shaft, a pair of spaced hammersupporting plates pivotally mounted at their inner ends on said pivot shaft, a hammer head adjustably mounted between the outer ends of said piates and having spaced working faces on its periphery, a locking bolt movably mounted between said plates with its outer and shaped to lockingly engage the adjacent portion of the hammer head when the desired working face is in working position, the inner portion of said locking bolt having an opening into which said pivot shaft fits at locking position of said locking bolt and having an extension of said opening reaching out to one lateral edge of said bolt, allowing the inner end of said bolt to be swung lateraJy until the said shaft is outside said extension opening whereupon the said bolt may be disengaged from the hammer head, and a releasable holding member normally rigidly connecting the locking bolt and at least one of said hammer-supporting plates when the locking bolt is in outward locking position but adapted to be released and allow the locking bolt to be retracted to non-locking position.

7. A hammer unit for a grinding mill comprising a pivot shaft, a pair of spaced hammersupporting plates pivotally mounted at their inner ends on said pivot shaft, a hammer head adjustably mounted between the outer ends of said plates and having spaced working faces on its periphery, a locking bolt movably mounted between said plates with its outer and shaped to lockingly engage the adjacent portion of the hammer head when the desired working face is in working position, the inner portion of said locking bolt having an opening into which said pivot shaft tits at locking position of said looking bolt and having an extension of said opening reaching out to one lateral edge of said bolt, allowing the inner end of said bolt to be swung laterally until the said shaft is outside said extensionopening whereupon the said bolt may be disengaged from the hammer head, and a holding bolt detachably inserted through the intermediate portions of the supporting plates and of the locking bolt to rigidly connect them when the locking bolt is in extended and locking position but adapted to be removed and permit the locking bolt to be moved to non-locking position.

WALTER J. CLEMENT. 

